- making oscimap default backend

- added about-screen
- added TreeTile for Tile lookup, dropping that HashMap
- using simple line-shader instead of std-derivatives one,
  about twice as faster here
- use distance calculation from MapRenderer - removing TileScheduler
- no need for MapGeneratorJob, pass MapTile directly to MapWorkers
- added two-finger tap gestures for zoom-in/out
- added tub/tron rendertheme
- started caching for oscimap
- add x/y coordinates to MapPosition, using it in MapRenderer
- create tag hash when needed
- no need for long tile coordinates max zoomlevel 31 should suffice

res/values-de/strings.xml

@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <resources>
-	<string-array name="preferences_map_generator_values">
+	<!-- <string-array name="preferences_map_generator_values">
 	  <item>Mapfile</item>
 		<item>PostGIS</item>
 		<item>OpenScienceMap</item>
-	</string-array>
+	</string-array> -->
 
 	<string-array name="preferences_scale_bar_unit_values">
 		<item>angloamerikanisch</item>